The effect of fertilizer on the use of soil moisture and the productivity of sugar beets in short crop rotations

Abstract

Goal. To create conditions of stable moisture supply and to achieve high productivity of sugar beets in short crop rotations by optimizing their structure and fertilizer system. Methods. A long-term field study to determine the effect of fertilizers on the yield and technological quality of sugar beet root crops; thermostatic-weight — to determine the moisture content in soil samples; calculation — to determine moisture reserves in the 1.5 m soil layer at the beginning and end of the growing season and the use of moisture by sugar beet plants. Results. The results of research on the impact of organo-mineral fertilizer systems on soil moisture availability and biological productivity of sugar beets in short grain-beet crop rotations are presented. It was found that at the beginning of the sugar beet growing season in crop rotations, large reserves of productive moisture (225–270 mm) were accumulated in the 1.5 m soil layer per hectare. The structure of crop rotation had a greater influence on soil moisture than the fertilizer system. Under the mineral fertilizer system (N48.8P45K55 per 1 ha of crop rotation), moisture reserves in the soil layer of 1.5 m per 1 ha in crop rotations with precursors (barley — peas and peas — vetch-oat) were higher than in the crop rotation with two soybean fields by 25–38 mm. With the combined application of organic and mineral fertilizers, the reserves of productive moisture in the soil layer of 1.5 m at the beginning of the sugar beet vegetation on 1 ha increased by 5–27 mm compared to the mineral fertilizer system. It was found that sugar beet soil moisture was most effectively used with the combined application of mineral fertilizers, by-products, and green mass of the intermediate sideral culture of white mustard in the rotations of barley — peas — winter wheat — sugar beets and soybean — soybean — winter wheat — sugar beets. It was found that the highest biological productivity of sugar beets in short grain-beet crop rotations under conditions of sufficient moisture was provided by the application of N48.8P45K55 + siderate + side products per 1 ha of crop rotation; at the same time, the structure of crop rotation had a lesser effect on productivity indicators. Conclusions. In crop rotations with barley — peas and peas — vetch-oat, the reserves of productive moisture in the 1.5 m soil layer at the beginning of the growing season were 15–17 mm higher than in crop rotations with soybeans. Application of N48.8P45K55 + siderate + by-products in crop rotations of barley — peas — winter wheat — sugar beets and soybean — soybean — winter wheat — sugar beets ensured the lowest moisture consumption for the formation of a biological crop of sugar beets (305 m3/t) with a decrease to the background of mineral fertilizers for 24–31 m3. The highest biological productivity of sugar beets was achieved in the crop rotation of barley — peas — winter wheat — sugar beets with the application of N48.8P45K55 + siderate + side products per 1 ha of the crop rotation: sugar yield — 13.2 t/ha with exceeded background of mineral fertilizers by 1.8 t/ha; similar options in crop rotations with soybeans and peas — vetch-oat — at 0.6 t/ha.